数独问题.题目如下:

*--------------------------------------------------------------------------------------------*

| 7 8 3| 6 4 5| 2 1 9|

| 9 5 1| 2 8 7| 3 4 6|

| 6 2 4| 1 9 3| 7 5 8|

|------------------------------+------------------------------+------------------------------|

| 5 3 9| 4 6 2| 8 7 1|

| 1 4 6| 5 7 8| 9 2 3|

| 2 7 8| 9 3 1| 4 6 5|

|------------------------------+------------------------------+------------------------------|

| 4 6 2| 3 5 9| 1 8 7|

| 3 1 7| 8 2 6| 5 9 4|

| 8 9 5| 7 1 4| 6 3 2|

*--------------------------------------------------------------------------------------------*